AISI P20 Steel Round Bar Sheet Plate, DIN 1.2311, SCM4

P20 steel round bar sheet plate has many excellent properties. In the pre-hardened status, the mold can be processed without any heat treatment. Which cut down the running period and improves efficiency. After it has been processed through the forged, 1.2311 steel becomes dense. Then it can pass 100% ultrasonic test. And after the test, there will be no pores left and no defect. And it also is called DIN 1.2311 and SCM4 steel. P20 tool steel chemical composition and more information as below.

P20 Steel Round Bar Sheet Plate Supply Range
Round BarDia: 20-1000mm;
Other specifications can be customized.
Black, Rough Machined, Turned or as per given requirements.
Sheet/Plate/SlabThickness: 130-650mm; Width: 205-2200mm;
Other specifications can be customized.
Black, Rough Machined, Turned or as per given requirements.
BlockThickness: 130-650mm; Width: 205-810mm;
Other specifications can be customized.
Black, Rough Machined, Turned or as per given requirements.

P20 Steel Grade Equivalent Chart

Country USA Germany/UK/France ISO
Standard ASTM A681-08 Alloy Tool Steel EN ISO 4957: 1999 Tool Steel ISO 4957: 1999 Tool Steel
Grades P20 35CrMo7/1.2311 35CrMo7

Delivery condition: pre-hardened (28-34HRC)

with black or bright surface.  

Quality control: 100% UT (Ultrasonic Testing),

UT Standard is SEP 1921-84 C/c.

P20 Steel Chemical Composition

STAND C(%) Mn(%) P(%) S(%) Si(%) Cr(%) Mo(%)
ASTM A681-08 Alloy Tool Steel 0.28-0.40 0.60-1.00 ≤0.030 ≤0.030 0.20-0.80 1.40-2.00 0.30-0.55
EN ISO 4957: 1999 Tool Steel 0.30-0.40 0.60-1.00 - - 0.30-0.70 1.50-2.00 0.35-0.55
ISO 4957: 1999 Tool Steel 0.30-0.40 0.60-1.00 - - 0.30-0.70 1.50-2.00 0.35-0.55

1.2311 Steel Physical Properties

Density Specific Gravity Modulus of Elasticity Thermal Conductivity Machinability
0.284 lb/in3(7861 kg/m3) 7.86 30 x 106 psi(207 GPa) 24 Btu/ft/hr/°F 41.5 W/m/°K 60-65% of a 1% carbon steel

P20 Steel Mechanical Properties

Properties Metric Imperial
Hardness, Brinell(typical) 300 33
Hardness, Rockwell C(typical) 30 30
Tensile strength, ultimate 965-1030 MPa 140000-150000 psi
Tensile strength, yield 827-862 MPa 120000-125000 psi
Elongation at break(in 50 mm (2")) 20.0% 20.0%
Compressive strength 862 MPa 125000 psi
Charpy impact(V-Notch) 27.1-33.9 J 20.0-25.0 ft-lb
Poisson's ratio 0.27-0.30 0.27-0.30
Elastic modulus 190-210 GPa 27557-30457 ksi

P20 Steel Application


P20 steel is used to make thermoplastic molds, extrusion dies, injection molds and die casting dies. And can also be used to make main components of heavy-duty mold. In addition, it also be used to produce cold structural parts, TV cases, washing machines, inner casings of refrigerator and buckets. Of course, 1.2311 steel can also be used to make bumper dies for automobiles or structural components of cars. 1.2311 steel has very good hardness and plasticity. So it can be used to make a variety of molds.

The Method of Use

1.2311 steel has been pre-hardened to 285-330HB(30-36HRC), which can be used directly for mold making and process. It also has the characteristics of good dimensional stability. Just Pre-hardened steel can meet the needs of the industry. The die life can reach 50W mode times.

P20 Steel Round Bar Sheet Plate Heat Treatment

Stress Relieving

Preheating: Because mold steel 1.2311 steel plate is sold in a pre-hardened condition, hardening heat treatment is not necessary. After machining and intermittently during service, the steel must be thermally stress relieved by heating to 900ºF (482ºC), equalizing and holding for one hour per inch (25.4mm) of thickness, and cooling in air to ambient temperature.

In those rare circumstances where the AISI steel P20 must be re-hardened, the steel must first be annealed prior to hardening.


Critical Temperature: Ac1: 1405ºF (763ºC)

Preheating of P20 metal: Heat at a rate not exceeding 400ºF per hour (222ºC per hour) to 1150-1250ºF (621-677ºC) and equalize.

Austenitizing (High Heat)

Heat rapidly from the preheat to 1550ºF (843°C). Soak for 30 minutes for first inch (25.4mm) of thickness, plus 15 minutes for each additional inch (25.4mm).


Pressurized gas, or interrupted oil to 150-125ºF (66-51ºC).
For oil, quench until black, at about 900°F (482°C), then cool in still air to 150-125°F (66-51°C).


1.2311 tool steels are tempered at 482-593°C (900 to 1100°F) for a Rockwell C hardness of 37 to 28.


Annealing for AISI P20 tool steels takes place at 760-788°C (1400 to 1450°F) and then the steels are cooled slowly in the furnace at a temperature less than 4°C (40°F) per hour.

1.2311 Tool Steel Forging

1.2311 steel plate and round bars materials are forged at 1093°C (2000°F) down to 899°C (1650°F). Forging below 871°C (1600°F) is not recommended for these steels P20 material.


We have our own cutting and processing equipment. Specifications can be cut and customized according to your requirements.

We are professional special steel stockist and supplier with a high-quality stand for many years. Please contact us for any request of P20/1.2311 steels materials. Songshun Steel always with you.

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